Processes for purifying sulfurized hydrocarbon products



1 avoided.

United States Patent PROCESSES FOR PUREFYlNG SULFURIZED HYDROCARBON PRODUCTS Edward P. Cashman, Bayonne, and Richard E. Merz,

Plainfi'eld, N. 1., a'ssi'gnors to Esso Research and Enginearing Company, a corporation of Delaware No Drawing. Application December 23, 1952,

Serial No. 327,675

10 Claims. (Cl. 260-139) The present invention relates to sfulfurized hydrocarbon products which have utility as addition agents for lubricents and the like and relates more specifically to a method for purifying such products.

It is known that excellent addition agents for lubricating oils may be prepared by sulfurizing 'olefinhydrocarbons, especially the polymers of low molecular weight olefins such as the polymers of propylene, butylenes, amylenes and the like. Although these materials may be sulfurized by heating with free sulfur, a-more satisfactory product from the standpoint of oil solubility, lack of copper'staining tendency and odor can be obtained by sulfurizing with a sulfur halide, such as sulfur monochloride or sulfur dichloride. It is difficult to free the resulting product from a considerable proportion of the halogen. Amounts of halogen as high as 10% or greater remain in the-sulfurized product even after heating for long periods of time. Such amounts of halogen are quite objectionable, particularly where corrosion is to be One procedure that has been used successfully for dehalogenating 'such products has been that of heating the material with an aromatic. compound such as a phenol. This step drives oif subtsantially all of the chemically combined halogen and forms a product that is not excessively corrosive to metals. related aromatic compounds, however, form degradation products which remain as dark colored bodies in the final product. It is diificult to remove the degradation prod nets, and lubricants containing the additive are impaired in color and copper staining tendency. This adversely affects the marketability of such lubricants.

It is also known to treat the sulpho-halogena ted product described above with catalytic amounts of secondary or tertiary saturated monohydric aliphatic alcohols in order to form an improved product. Although this mode of treatment forms a product 'of relatively good color characteristics, the alcohols are generally not sufiiciently effective catalysts to reduce the halogen to commercially acceptable values. In general, it is desired to produce compounds containing less than about 2 to 3% halogen, preferably below 1% halogen. It is usually not possible to accomplish this with the monohydric alcohols even when using excessive amounts of alcoholic treating agents or severe treating conditions that generally cannot be tolerated in commercial operations.

In accordance withthe present invention, an aliphatic or cycloaliphatic hydrocarbon that has been sulfurized by 'means of a sulfur halide can be dehalogenated with little difliculty by merely heating such product containing hydrogen. halide impurities with a non-aromatic organic compound containing at least two hydroxyl groups. Such polyhydroxy compounds are not only superior to phenols and monohydroxy aliphatic alcohols as dehalogenation agents under comparable treating conditions, but they also form products having excellent color characteristics The phenols and otherand. little tendency to stain copper and are superior in these respects to the prior art products.

2 ,768,157 Patented Oct. 23, 195 6 Advantageous results may be obtained by employing quantities of the polyhydroXy compounds ranging from about 1 to 25% by weight, preferably 3 to 15% by weight, based on the sulfurized hydrocarbon product. The treating temperature range that may be employed is from about to about 350 F., more preferably from about 175 to 300 F. It will generally be found convenient to conduct the treating operation at a reduced pressure for times in the range of about 0.5 to 10 hours in order to insure substantially complete removal of halogen. After the heating step, the product may be steamed, blown with an inert gas or otherwise treated to remove any traces of unreacted hydrocarbon, hydrogen halide or other contaminating materials.

It is not desired to be bound by theoretical considerations, but apparently the action of the polyhydroxy compound in effecting dehydro-halogenation is mainly catalytic. A small proportion of the p'olyhydroxy material, however, may enter into chemical combination with the sulfurized hydrocarbon.

The hydrocarbon materials, which may be sulfu'rized by sulfur halides and then reduced in halogen content by the method of the present invention, include any aliphatic or alicyclic hydrocarbons containing an unsaturated carbon-to-carbon linkage. This group of materials includes the olefins, e. g., propylene, butyle'nes, diisobutylenes, triis'obutylenes, the codirner of isobutyleneand 1'1- butylene, carcked gasoline fractions, cracked parafiin wax, viscous olefin polymers such as medium or high molecular weight polybutene, cyclopentene, 'cycloheigen'e, butadiene, pentadiene, 'isoprene and the like. Likewise the process may be applied to compounds having acetylenic linkages, CEC. Olefins of less than 4 carbon atoms are not generally employed in preparing sulfurized lubricating 'oil additives, although products prepared from such olefins may be purified by the method of the present invention. Derivatives of the above described compounds containing various substituent groups and atoms may be used to advantage since the substituent groups normally do not interfere with the sulfurizat'ion reaction or the purifying process herein described. Such substituted derivatives may include olefins having attached aromatic nuclei, halogen atoms, nitro groups, etc.

For the preparation of the sulfuriz'ed hydrocarbons and the like, the most suitable sulfur halides are sulfur dichloride and monochloride, especially the latter. The olefinic material and sulfur halides are generally reacted in ratios of olefinic material to sulfur halide within the range from about 3:1 to 1:1 molal ratio. Higher ratios of olefinic material are sometimes used when a portion of the same is to serve asa solvent to be removed later as unreacted material. The temperatures which have been found most satisfactory for this reaction are from about 70 to F., but the method may be carried out at considerably higher or lower temperatures if desired. Caterlysts are notrequired.

The polyhydroxy organic compounds which maybe employed as dehalogenation catalysts in the pnesent inven tion are preferably polyhydroxy aliphatic and alicyclic alcohols, although compounds containing ether linkages between carbon atoms, such as polyhydroxy ether alcohols or those containing other substitutent groups may also be used. Such compounds may contain 2, 3, 4- or even more hydroxyl groups in the molecule. They may be straight chain or branched in character and may have low, medium or high molecular weights. Suitable compounds include ethylene glycol, propylene glycol, LZ-but'anedidl, glycerol; erythritol; erythrol; pentaerythritol; diethylene glycol; triethylene glycol; dipropylene glycol; octylene glycol; 1,1(Ldecanediol; 1,2-cyclopentanediol; and the like. The higher molecular weight polyhydroxy compounds include such materials as polyethylene glycols hav- 3 ing molecular weights as high as 200, 500, 1,000, 6,000,

and higher.

The most effective compounds of this class are generally those having in the range of 3 to 20 carbon atoms, preferably in the range of to 12 carbon atoms. The above is only a partial list of the types of materials that may be used in the practice of the present invention, and it will be obvious to the skilled workman that other compounds of this general class may be selected for practicing the invention.

The following examples illustrate the application of the present invention in purifying a sulfurized diisobntylene. These examples, however, are not to be considered as limiting the scope of the invention in any manner.

Example 1.C0mparison of various hydroxy compounds as delzalogenation agents Product A.-This product was prepared in a 3-liter 4-necked flask equipped with a mechanical agitator, dropping funnel, thermometer and gas outlet. 975 g. of diisobntylene were placed in the flask and 391 g. of sulfur monochloride was added slowly over a period of one hour at a temperature of 72 to 115 F. After agitating for one hour at approximately 100 F., 44 g. of octylene glycol (5.3% by weight, based on the sulphochlorinated material) was added and heat was applied to the reaction mixture. Distillation equipment was attached to the flask in order to take over any evolved gas, excess diisobutylene, and light ends. The material was heated to a temperature of 230 F., vacuum was applied slowly to the system and the reaction mixture was held at 400 mm. Hg absolute for 6 hours at this temperature. At the end of this time, the reaction mixture was steamed to remove any traces of diisobutylene, hydrogen chloride and light ends. The product was then dried.

Product B.This product was prepared by the procedure used in preparing Product A except that 44 g. of phenol were used in place of octylene glycol as the dehalogenation catalyst.

Product C.This product was prepared by the procedure used in preparing Product A except that 44 g. of 2-ethyl-hexyl alcohol were used in place of octylene glycol as the dehalogenation agent.

Each of the above products were analyzed for sulfur and chlorine contents, and Tag-Robinson colors were determined on mixtures containing 25% of the product in a light hydrocarbon, water white solvent. Copper strip staining ratings were also determined. Pertinent yield, analytical and other inspection data are shown Example 2 A series of runs were carried out under conditions similar to those used in preparing Product A. The amount of the octylene glycol catalyst was varied in the range of 2.5 to 10% by weight, based on the sulphochlorinated material. Maximum reaction temperatures in the presence of the glycol were also varied. The results of these runs are shown in Table II below:

TABLE II Octylene Product Analysis, Glycol Weight Percent Dehalogenation Temperature, F. Used,

Weight Percent Chlorine Sulfur Example 3 A series of runs were carried out using procedures similar to those described in the preparation of Products A, B and C with the exception that various other polyhydroxy compounds, alcohols and aromatic compounds were employed as catalysts. In most cases, 10% by weight of catalyst, based on the product treated, was

used. The results are tabulated in Table III as follows:

TABLE III Inspections on Final Product Catalyst Employed Chlorine, Sulfur, Tag-Rob- Weight Weight inson Color Percent Percent (25% in Solvent) Polyhydroxy Aliphatic Compounds:

Ethylene glycol 3. 3 28.1 10% Propylene glycol 1. 3 24. 6 9+ Diethylene glycol 1 7 24. 7 10 Triethylene glycol 1. 6 24. 4 10 Dipropylene glycol 1. 6 23. 7 9+ Polyethylene glycol (6,000 avg.

mol. wt.) 2. 4 23.2 12% Phenols:

Tri-amyl phenol"... 0. 7 22. 0 M Hydroquinone 2.1 1 (dark) Alcohols:

Isopropyl 2 3. 2 17. 0 0 0-013 Alcohols 3 1. 7 21. 5 3% 1 Not determined.

2 Used 40 o by weight of alcohol, based on treated product.

in Table I below: 3 Lorol alcohols having average molecular weight of about 207.

TABLE I Inspections on Finished Product Product Yield, Product Catalyst Weight Tag-Robin- Percent Sulfur, Chlorine, son Color Saybolt Copper Strip,

Weight Weight (25% in V18. 3 Hrs. 212 F. Percent Percent Solvent) 100 F. 0.5% in Oil 1 Octylene Glycol.-. 89 21. 6 0. 3 111-4 54. 9 Light Peacock. Phenol 87 22. 6 0. 9 A 61. 7 Black Deposit. 2-Ethyl Hexanol 85 24 4. 9 10 62. 9 Light Peacock.

SAE-20 grade mineral lubricant.

The octylene glycol was superior to either phenol or 2-ethyl hexanol as a dehalogenation catalyst both as regards chlorine content and yield of product. The glycol also produced a material having markedly superior color characteristics to that produced when using phenol as catalyst and somewhat better than that when using the monohydroxyl alcohol. Also the glycol produced a material markedly superior in copper staining tendencies to the material produced by phenol catalyst. It is interesting to note that the chlorine content of the alcoholtreated product was approximately 16 times greater than that obtained when using the glycol.

C18 alcohols degraded the color of the final product.

The present invention is not to be considered as limited by any of the specific embodiments or examples herein disclosed, but is to be limited solely by the terms of the appended claims.

What is claimed is: V

1. A method of dechlorinating a sulfurized olefin which has been obtained by reacting a member selected from the group consisting of olefins and polymers thereof with a sulfur chloride, which comprises heating said sulfurized olefin in the presence of a polyhydroxy aliphatic organic compound containing from 3 to 20 carbon atoms at a temperature in the range of about 100 to about 350 F.

2. A method as in claim 1 wherein said po'lyhydroxy compound contains 2 hydroxyl groups.

3. A method as in claim 2 wherein said polyhydroxy compound is propylene glycol.

4. A method as in claim 2 wherein said polyhydroxy compound is diethylene glycol.

5. A method as in claim 2 wherein said polyhydroxy compound is triethylene glycol.

6. A method as in claim 2 wherein said polyhydroxy compound is dipropylene glycol.

7. A method as in claim 2 wherein said polyhydroxy compound is octylene glycol.

8. A method of dechlorinating sulfurized diisobutylene which has been formed by reacting diisobutylene with a sulfur chloride which comprises reacting said sulfurized diisobutylene in the presence of about 1 to by weight of a glycol having in the range of 5 to 12 carbon atoms at a temperature in the range of about to 350 F.

9. A method of dechlorinating sulfurized diisobutylene which has been obtained by reacting diisobutylene with sulfur monochloride which comprises heating said sulfurized diisobutylene with octylene glycol at a temperature in the range of about to 300 F., for a period in the range of about 0.5 to 10 hours, said glycol being used in an amount in the range of 3 to 15% by weight, based on said sulfurized diisobutylene.

10. As a new composition of matter, the product produced by the process of claim 1.

References Cited in the file of this patent UNITED STATES PATENTS 

1. A METHOD OF DECHLORINATING A SULFURIZED OLEFIN WHICH HAS BEEN OBTAINED BY REACTING A MEMBER SELECTED FROM THE 